A number of systems and programs are offered on the market for the design, the engineering and the manufacturing of objects. CAD is an acronym for Computer-Aided Design, e.g. it relates to software solutions for designing an object. CAE is an acronym for Computer-Aided Engineering, e.g. it relates to software solutions for simulating the physical behaviour of a future product. CAM is an acronym for Computer-Aided Manufacturing, e.g. it relates to software solutions for defining manufacturing processes and operations. In such computer-aided design systems, the graphical user interface plays an important role as regards the efficiency of the technique. These techniques may be embedded within Product Lifecycle Management (PLM) systems. PLM refers to a business strategy that helps companies to share product data, apply common processes, and leverage corporate knowledge for the development of products from conception to the end of their life, across the concept of extended enterprise.
The PLM solutions provided by Dassault Systèmes (under the trademarks CATIA, ENOVIA and DELMIA) provide an Engineering Hub, which organizes product engineering knowledge, a Manufacturing Hub, which manages manufacturing engineering knowledge, and an Enterprise Hub which enables enterprise integrations and connections into both the Engineering and Manufacturing Hubs. All together the system delivers an open object model linking products, processes, resources to enable dynamic, knowledge-based product creation and decision support that drives optimized product definition, manufacturing preparation, production and service.
CAD systems provide an intuitive and flexible user interface for designing precise 3D mechanical parts, from sketching in an assembly context to iterative detailed design. Such a solution is provided by CATIA Part Design (trademark) application which combines the power of feature-based design with the flexibility of a Boolean approach, offers a highly productive and intuitive design environment with multiple design methodologies, such as post-design and local 3D parameterization.
During the process of mechanical parts design, the designer may need to create several identical features from an existing one and to simultaneously position them on a part. To this aim, the designer generally uses patterns that allow to duplicate an original feature at a location chosen in the part by the designer. Common patterns are rectangular pattern and circular pattern. The designer may also need a particular pattern (also referred to as user pattern) that is created by hand by the designer. For instance, the designer selects a set of points on which the original feature will be duplicated.
The creation of a circular staggered pattern of objects requires performing several steps, as illustrated on FIGS. 2 to 4. First, the designer creates an initial part comprising a reference object and a duplicate reference object; for instance, on FIG. 2, a circular pad 200 comprises a first hole 202 that is the reference object and a second hole that is the duplicate reference object 204. The duplicate reference object is placed on the pad with an angular shift θ from the reference object and a distance d2 from the centre O of the pad which is larger that the distance d1 between the reference object and the centre O of the pad. Next, the designer creates a first pattern by duplicating the reference feature according to a circular pattern, as shown on FIG. 3. Then, the designer creates a second pattern for duplicating the duplicate reference feature according to a circular pattern. Finally, the first and second patterns are combined or merged for obtaining the requested staggered pattern, as illustrated on FIG. 4.
The creation of a staggered pattern of objects can also be performed by using a user pattern. It consists in creating a sketch of point representing each location of duplicate reference features, and creating a pattern by selecting a reference feature to duplicate and the sketch of points. Again, several steps are required.
Likewise, the modification of a pattern requires the designer to perform several steps. For instance, starting from a circular staggered pattern of objects as the one illustrated on FIG. 4, the designer has to modify the angular shift of the duplicate reference feature (such as the duplicate reference feature 204 on FIG. 2) in relation with reference feature (such as the reference feature 200 on FIG. 2). Then, the designer has to edit the first and second patterns and reduce the number of instances of the reference feature. Finally, the modified part is obtained.
The creation and the modification of a circular staggered pattern of objects thus require the designer to perform several steps. It requires added actions to create the geometry (e.g. creation of an angular shift, creation of two patterns, or creation of sketch), which is a cumbersome task and time consuming as well.
Within this context, there is still a need for an improved method for designing a circular staggered pattern of objects in a computer-aided design system.